Michigan cancer center is first to acquire MR linac radiation therapy system

The Henry Ford Cancer Institute in Michigan is the first facility to acquire a radiation therapy system that uses linear accelerator technology embedded in an MRI scanner, allowing more precise treatment with real-time visualization.

The system, the ViewRay MRIdian Linac, was approved by the FDA in February, and is currently the only FDA-approved linear accelerator-based MR-guided radiation therapy system.

The unit is being installed at the Cancer Institute at Henry Ford Medical Center-Cottage in Grosse Pointe Farms and will be ready for use next month.

“It allows us to be able to visualize and not only see the tumor itself within the body,” Dr. Benjamin Movsas, chair of the radiation oncology department at the Cancer Institute, told HCB News. “It’s just as important to also see the normal tissues surrounding the tumor in real time. It’s kind of like taking off the blindfold, so to speak, so we can make sure we really tailor the treatment to where it needs to go.”

The imaging, usually a CT scan, has traditionally been done before treatment. Tumors in the liver, pancreas and lungs tend to move during therapy, and live MR imaging can visualize the movement.

“This novel approach allows you to make real-time adaptive changes,” Movsas said. “You can, on the fly, change things and re-plan, and re-target where appropriate.”

Mike Saracen, senior marketing director for ViewRay, said there had been a technical barrier to getting the linear accelerator technology to work with the magnetic field of the MRI scanner. To overcome this, the company created a magnetic shielding technology. It also prevented the linear accelerator from distorting the image with a patented radio frequency-absorbing material, similar to technology used on stealth aircraft.

At the European Society for Radiotherapy & Oncology (ESTRO) meeting in May, Elekta unveiled the Elekta Unity, which also combines MR and linear accelerator technology. The product is awaiting a CE Mark.